Production processing tools process a component to facilitate the production of a product. A production processing tool may transport the component, perform work on the component, or test the component, among other possible tasks performed by the tool.
In a production process, one or more tools may be thought of as a group. Tools in a group may all perform the same process step, or may perform different process steps. Tools in a group may be operated by one or more operators. In many circumstances, however, the tools in a group facilitate one or more related steps in a production process.
When two or more tools in a group are operated by a single operator, or controlled by a single controller, the efficiency of each individual tool may be decreased. For example, if an operator idles all tools in a group to load them, then operates them all simultaneously, tools will be idled while other tools are loaded. This reduces the efficiency of each tool in the group, but may increase the efficiency of utilization of the operator by spreading the cost of the operator across multiple tools.
To estimate production quantities of a production system, the throughput and yield of each tool used individually may be measured, and the measurements adjusted to take into account the loss of efficiency due to the configuration of each tool in the group. Based on parameters of the production process, the production process may be simulated and certain production quantities may be calculated, such as the number of units of a material to start in the production process to achieve a certain number of units required at the output.
However, many modern production process tools are controlled by tools in other groups. The production quantities of one group can therefore be interrelated with the production quantities of the controlling tool group. If the controlling tool group is not operational, the tool group controlled by the non-operational tool group will be out of operation as well, affecting the production quantities. Conventional simulation tools do not account for this fact, making the production quantities calculated by these simulators erroneous.
What is needed is a method and apparatus for more accurate calculation of production quantities.